Interlocking system for railroads



July 8, 1941. N. B. COLEY ETAL v INTERLOQKING SYSTEM FOR RAILROADS Fil ed June a, 1959 4 Sheets-Sheet 1 Jam- FIG. LA.

I I .l I 5M1 .4, I I I I III LIII I I oIey c222 MCiTwiTcheII THEIR ATTORINEY INVENTORS July 8,1941.

N. B. COLEY ETAL INTERLOCKING SYSTEM FOR RAILROADS Filed Jun :5i 1939 4 Sheets-Sheet 2 d In W T ,mMMM N d m E n T W A .v R b H rwY BU N -i RAH ll wlll 1 5 y 1941- N. B. COLEY ETAL 2.248.660

INTERLOCKING SYSTEM FOR RAILROADS Filed June 3, 1939 4 Sheets-Sheet 4 I l I. I v I I t-'- I w I l I we):

ama 51 INVENTORS c-zfi ever5e NgColey a2; MCTWI'TcheH THEIR ATTORNEY Patented July 8, 1941 anaest- UNETED STATES PATENT OFFICE INTERLOCKING SYSTEM FOR RAILROADS Nelson B. Coley, Rochester, and Morton C.

Twitchell, Spencerport, N. Y., assignors to General Railway Signal Company, Rochester, N. Y.

Application June 3, 1939, Serial No. 277,150

Claims.

This invention relates in general to interlocking systems for use on railways, and has more particular reference to an interlocking system and a derail at each of the four entering ends of the track layout, and with independently operable track switches controlling the two turnouts.

The syste.-, when in normal condition, has all the various parts positioned in their normal positions. That is, the wayside signals are at stop, the derails are positioned to be effective to derail a train passing over them, and the track switches are lined up with the through main derail machines are employed for moving the switches and derails from normal to reverse positions, and vice versa, in accordance with the operation of the machine in one direction or the other.

If the derails are not already positioned normal, they can be by means controlled by a manually operable lever, provided the corresponding lock relay be energized. These look relays for the derails, are energized if allroutes including the derail in question, are unoccupied, and the wayside signals for such routes are positioned at stop. There may be only one such route, or there may be several routes, all in accordance with the then positions of the track switches.

After the derails are positioned normal as described above, a route can be lined up by operation of the proper track switches, controlled by the movement of switch machine levers,.all provided that the lock relays for all derails in all routes including the switch in question, are energized. Here again there may be only one such derail relay, or there may be more, depending upon the then position of the other track switch or switches. To operate a switch it is also necessary that all the derails in all routes including the track switch in question, be positioned at normal. 7

With a route lined up as described above, with the switches properly lined, all derails in that route, but not in any of the conflicting routes, can then be operated to their reverse positions,

closed so as not to derail a train passing thereover. The operation of these derails to reverse locks all the track switches in the lined up route against operation.

With the route lined up as above, having the track switches closed and the involved derails positioned reverse, the signal for either direction of traflic over the route can be cleared, and circuits are so arranged that on clearing a signal for traflic in one direction, the lever for clearing the signal for traffic in the other direction,,if operated, cannot put the cleared signal to stop,

and cannot clear its own signal- To briefly summarize the above, with all the control devices at normal, the track switches can be operated to line up a route, whereupon the involved derails can be operated to reverse, which effects the locking up of the switches, and of the conflicting derails against operation. Then the signals can be'cleared'for either direction 1 of traffic, which results in preventing the other direction of traflic being set up, and prevents the lever for the other direction of traffic from putting the cleared signal to stop.

As the description progresses, further objects,

purposes and characteristic features of the intrack. Power operated switch machines and:

vention will appear, it being borne in mind that in all of the operations involved, free levers are employed, movable at any time, without any mechanical interlock therebetween. However, the relation between the operating means for the signals, the switches and'the derails is such that if any danger be involved, the lever movement is ineffective to produce any operation, all due to the electric interlock between the' various elements involved.

In the'drawings has been shown one embodiment of the present invention, given solely for the purpose of illustration, and set forth in a wholly diagrammatic manner, and without any intent whatsoever of limiting the invention to the precise form shown. In the-drawings:

Fig. 1 shows oneform of the invention in a wholly diagrammatic manner, and is comprised bottom of sheet 1A placed at the top of sheet 1C,

and with the right sidesof sheets 1A and 1G placed, respectively, at the left sides of sheets 1B and 1D.

Fig. 2' is a fragmentary diagrammatic figure showing correspondence contacts for the control of the track switch indication relays.

Referring now to the drawings, and first to the track layout shown in Fig. 1, there is here 7 represented, merely by way of example, for.

explaining the features of the invention, a stretch 20, of main track, with a siding 2| for west bound trafiic on the main track, and a siding 22, for east bound traflio on the main track. At

,...the entrance end of each track, is a signal, as

2, 4, 6 and 8. Controlling the sidings are track for track switch I; and each derail having a.

power operated detrail machine for operating it, as derail machine DM5, for derail 5.

For controlling each switch machine, there is a manual lever, such as SMLI, for the switch machine SM I, and this lever controls a WZ relay, as I WZ, by placing positive or negative energy on the machine, to cause it to operate the track switch to either normal or reverse position.

Each of the signals is controlled by a. manually operable lever, as for example, lever SG2 for signal 2. This lever controls a relay ZGZ which in turn controls a signal relay 2G which latter can place energy on one wire giving the stop or red indication, or another wire which gives a clear or caution indication, in accordance with trafiic conditions in advance, in the usual manner for such three-position signal control.

Each of the derails is controlled by means of a lever, as for example, the derail machine lever DML5, which controls a relay as 5WZ, for placing positive or negative energy on the derail operating machine DM5, whereby to position the derail in either its normal or its reverse position.

In the case of the two track switches, there are two switch position indicating relays, for indicating by their energized position, that the switch is in either its normal or its reverse position, and locked condition. In the case of switch I, these repeater relays are INWP and IRWP,

which are respectively energized or deenergized according as the track switch is positioned in its normal, or its reverse, position.

In connection with each of the derails, there are two repeater relays, as for example, the repeater relays SNWP and ERWP for derail 5. As in connection with the track switches, when derail 5 is in its normal or derailing position, relay SNWP is energized, and 5RWP is deenergized, while, when derail 5 is in its reverse position, that is, so as to permit a train to pass thereover without danger, the normal relay 5NW'P is deenergized and the reverse relay SRWP is energized.

Each of the track sections TI and T3 is supplied with a usual track relay, as IT and 3T respectively, each of which is energized or deenergized, according as its section is unoccupied or occupied.

Involved in the system are lock relays for the switches and for the derails, the lock relays ILRB and 3LRB being conveniently referred to as switch lock relays, while the lock relays ILRA and 3LRA can be conveniently referred to as derail lock relays. While the functions of these lock relays will be brought out more clearly as the description progresses, it may be helpful to point out at this point that the derail lock relays ILRA and 3LRA are energized when the switches and signals in all routes including the derail in question, are positioned normal. The switch lock relays ILRB and 3LRB are energized when the corresponding derail lock relays are energized, and in addition when the derails included" in any route including the switch in question, are positioned normal,

To explain the operation of the present system it would appear sufficient to consider clearing one route through the system, as for example, the route for an east bound train from signal 2 to signal 8 which route includes the track switch I and the track circuit IT, and the two derails 5 and II, provided that conflicting routes do not exist.

The system normally has all of its various instrumentalities in their normal positions or conditions, that is, all the signals are at stop, all the derails are at normal, and the track switches are lined up for the main track.

If any of the derails should not be positioned at normal, they can be so positioned by operation of the respective manually controlled lever, provided only that the corresponding derail lock relay is energized, and this requires that on all routes including the derail in question, the signals shall be at stop and the track sections shall be unoccupied.

For example, assume that derail 5 is reverse, (and lever DML5 is to the right) and that it is desired to operate it to normal so that a route can be lined up by operation of the proper track switches. On movement of lever DML5 to he left, the control relay 5WZ is picked up and is then stuck up through an obvious circuit, to place positive energy on the derail machine DM5, provided lock relay ILRA is energized, the circuit including lever DML5, contact finger 24 and front point of lock relay ILRA, and the control relay 5WZ.

The circuit for energizing lock relay ILRA differs in accordance with whether the route 28 is the only one which includes the derail 5, or whether there is another route such as 26 which includes this derail, and this latter is the case if track switch 3 is positioned normal. In either case, the lock relay is energized if the track sections and signals of all routes including the derail are, respectively, unoccupied, and at stop. The energizing circuits for lock relay ILRA includes contact finger 25 and back point of relay 2G, contact finger 26 and back point of relay ZGZ, contact finger 21 and front point of track relay IT, winding of relay ILRA, contact finger 28 and back point of relay 8G, contact finger 29 and back point of relay 8GZ, and then, if track switch 3 ,:be positioned reverse, this circuit passes through contact finger 30 and front point of relay 3RWP. If, however, track switch 3 be positioned normal, whereby to include a second route from signal 5 to signal 2 which includes the derail 5 in question, then the circuit includes contact finger 3 I and back point of relay GGZ, contact finger 3I and back point of relay 6G, contact finger 32 and front point of track relay 3T, and contact finger 33 and back point of relay 4G.

With the parts all positioned normal, we can assume that it is desired to line up a route from signal 2 to signal 8, and then clear the signals for an east bound train to pass over this route.

In general, in the present system, the order of operation of the parts is first the track switch,

up the control relay 2GZ, through a circuit. which includes lever SG8, contact finger 50 and back point of route relay-8BR, contactfingerl gized and hence permit operation of track switc I, requires that the corresponding lock relay ILRA be energized, and in addition that the derails in all routes including track switch I shall be at normal. Accordingly, there are two different energizing circuits for the lock relay ILRB since, with track switch 3 reverse, there is no conflicting route, whereas with track switch 3 normal, there is a conflicting route or, in other words, a second. route including the track switch I.

One energizing circuit for relay ILRB, when track switch 3 is positioned reverse, includes contact finger 35 and front point of relay HNWP, contact finger 36 and front point of relay 3RWP, contact finger 31 and front point of lock relay ILRA, the winding of lock relay ILRB, and contact finger 38 and front point of relay 5NW'P. The other circuit for energizing this lock-relay includes contact finger 39 and front point of relay'llNWP, contact finger 4!! and front point of relay 9NWP, contact finger 4| and front point of lock relay SIRA, contact finger 42 and front point of lock relay ILRA, contact finger 43 and front point of relay 'INWP, the winding of lock relay ILRB, and contact finger 38 and front point of relay 5NWP.

With the route lined up by the movement of switch I in reverse position, the next step is to operate the details in this route. To operate derail 5 to reverse position, lever DML5 is moved to the right, or reverse position, to energize the control relay 5WZ, through a circuit including contact finger 43 and front point of relay IRVVP, contact finger 44 and back point of relay IN'WP, the control lever DML5, contact finger 24 and front point of lock relay ILRA, and the winding of control relay 5WZ, whereby to place negative energy on machine DM5 to move the derail 5 to reverse.

Had the track switch I been positioned normal, this circuit would have been interrupted at contact finger 44 of relay INWP, and it would then have been required, for the movement of this derail 5 to reverse position, that the track switch 3 had been positioned normal, whereby to complete the cincuit through contact finger 45 and front point of relay 3NWP, and contact finger 46 and back point of relay 3RWP. Thus, in order to place a derail in its reverse position, the track switches must be properly positioned for lining up all routes including the derail in question.

Derail II is operated in the same general manner as derail 5, by moving its control lever DMLH to the left, or reverse, position, whereby to pick up the control relay HWZ through contact finger 48 and front point, of reverse indication relay of track switch I, and contact finger 49 and front point of the lock relay ILRA.

Each derail control relay, as 5WZ, after being picked up, can be stuck up through an obvious circuit, including contact finger 24 and back point of lock relay ILRA, whereby to maintain the derail control relays energized after this look relay has been deenergized, which, of course, occurs on the clearing of one of the signals involved in its energizing circuit.

With track switch I positioned reverse, and the derails 5 and II positioned reverse, the signals for the route 2-8, for east bound traific, for example, can be properly controlled to clear signal 2.

To clear signal 2, signal lever SGZ is moved to the reverse or left hand position, to thereby pick and front point of relay HRWP, contact finger 52 and back point of relay INWP, contact finger 53 and front point of relay 5RWP, contact finger 54 and back point of route relay 2BR, control lever 8G2, and the winding of relay 2G2. Upon picking up, relay ZGZ sticks upthrough its own contact 55 and front point, through an obvious circuit. l

The picking up of the control relay ZGZ completes a circuit for the energization, in series of the two route relays 2BR and 8BR each of which has a back contact in the circuit just traced for relay 2GZ. The energizing circuit for these route relays includes contact finger 56 and back point of relay 8G, contact finger 51 and back point of relay 8GZ, the winding of relay ERR, contact finger 58 and front point of relay HRVVP, contact finger 59 and front point of 'relay IRWP, contact finger 60 and back point of relay INWP, contact finger BI- and back point of lock relay ILRB, contact finger 62 and back point of lock relay ILRA, contact finger 63 and front point of relay 5RWP, the winding of relay 2BR, and contact finger 64 and front point of relay 2G2. 3

The picking up of relays 2BR and 8BR breaks the circuit to the signal control relay' for the opposing signal 8, whereby the energy which sticks up the control relay ZGZ cannot pass through control lever SG2, contact finger 54 and back point, etc., to reach the heel of the control lever SG8, and .thus it prevents a subsequent movement of lever SG8 to reverse, from clearing the opposing signal 8, for the route set up.

It should be noted that in clearing signal 2, as

. described above, upon the energization of control relay ZGZ, the signal is not cleared, but the route relays ZRR, and 8BR, are energized to prevent any attempt from clearing the opposing signal 8, from being successful. It is only upori'the energization of the route relay 2BR- that a circuit is completed for energizing the signal control relay 2G of signal 2, this circuit including contact finger 65 and front point;and contact finger 66 and front point, of the relays 2BR and 2GZ respectively, and the winding of relay 2G, whereby to pick up contact finger 61, to thereby place energy on wire 69 to cause the signal to indicate either clear or caution in accordance with traffic conditions'in advance. I V

In connection with the signal controls, it is of course contemplated that any desired form of signal can be employed, such as semaphore signals, for example, but for simplicity it is assumed that a light signal of the type-S form is employed, having a single light source and a spectacle carrying various colored glasses which'ls movable in front of the light source to give the desired indication. In the case of signal 2, when energy is removed from wire '69, the signal mechanism is deenergized and the spectacle is biased to give the red indication. When energy is placed on wire 69, the mechanism is energized either in one direction or the other, in accordance with control by traffic in advance, to give either a green or yellow aspect, indicating proceed and traffic thereover, it can be seen that the derails can all be placed at normal, if not already. so placed, provided however that the involved track sections be unoccupied and the signals be at stop, this being assured by the employment of the lock relays ILRA and SLRA. In order that a switch be operated to line up a route, it is necessary that all derails involved be positioned normal, as assured by the lock relays ILRB and 3LRB, and that the track sections involved be unoccupied and the signals involved be at stop, as assured by the lock relays ILRA and 3LRA, front contacts of which are in the energizing circuits for the switch lock relays ILRB and 3LRB.

With the switches properly positioned, control is given over the derails in all routes properly lined up but not for any other derails. Upon operation of the derails one of the lock relays ILRB and 3LRB, as the case may be, is deenergized, to thereby lock the track switches against operation. Upon properly lining up the track switches and the derails, control is obtained of the signals involved in the lined up route, but of no other signals, and upon the clearing of the signals for travel in one direction over the route, the control of the signals for travel in the other direction over the route are withdrawn.

In restoring the system to normal, the signal levers can be operated to place cleared signals at stop, then the derail control levers can be moved to normal to restore the derails to normal, whereafter control of the track switches can be exercised to position the switches as desired.

It should be noted that all the levers involved in the control of the various instrumentalities are free to be moved at any time, and hence,it is a completely free lever control system. The control circuits are arranged, however, so that the various parts are interlocked to prevent any improper lining up of a route, or clearing of signals, regardless of lever movements. Furthermore, the highest degree of safety is obtained by employing the derails, as above described, in connection with the switches and signals, and so interlocking the derails and the signals and switches as to prevent any improper route being set up.

It is obvious, of course, from the above description, that the interlock is efiective to prevent an improper route being set up if some other route than the one described above is under consideration, and it would appear unnecssary to further extend the specification to. describe in detail the setting up of other routes possible in the track layout employed for the purpose of illustrating the principles of the invention.

The track switch indication relays, such as INWP and IRWP are controlled so as to reflect the extreme position and locked condition of the switch machine. The control of these relays also involves correspondence contacts whereby to insure that the energization of an indication relay shall not occur unless the track switch has followed the control relay and is in correspondence therewith.

In Fig. 2, if we assume that switch machine lever SMLI has been moved to the left, to the reverse position, to thereby position relay IWZ to the left, to place negative energy on the switch machine SMI, it is only after the track switch has been moved, to thereby move contactor '10 from its full line, normal, position to its dotted, reverse, position, before the reverse indicating relay IRWP becomes energized through a circuit including the winding of relay IRWP, contactor in reverse position, polar contact finger H to the left, and neutral contact finger l2 and front point.

The above rather specific description of one form of the present invention is given solely by way of example, and is not intended, in any manner whatsoever, in a, limiting sense. It is to be understood that various modifications and adaptations can be employed, without departing from the spirit or scope of the present invention, except insofar as it is limited by the appended claims.

Having described our invention, we now claim:

1. In a track layout for railway interlocking plants, a plurality of tracks, track switches in the tracks for lining up various routes, including conflicting routes, with each route including at least one track and a switch, a signal for each end of each route, an individual lever, freely movable at all times, and associated circuit means, for governing each signal, a derail positionable normal and reverse and between each signal and the adjacent track switch, individual power operable means for each derail and each switch, an individual lever freely movable at all times and associated'circuit means for governing each of the power operable means, circuit means preventing operation of an derail to normal unless all routes including the derail be unoccupied and all signals governing all routes including the derail be at stop, circuit means preventing operation of a track switch unless all routes including the switch be unoccupied and all signals for such routes be at stop and all derails in such routes be at normal, and circuit means locking against operation of a derail to reverse unless the track switches for a particular route including the derail be properly lined up and for :locking all such track switches against operation so long as the derail is in its reverse position.

2. In a track layout for railway interlocking plants, a plurality of tracks, track switches in the tracks for lining up various routes, including conflicting routes, each including a switch and at least one track, a signal for each end of each route, a derail movable to normal and reverse and between each signal and the adjacent track switch, an individual lever, freely movable at all times, and associated circuit means for governing each signal, individual power operable means for each derail and for each switch, an individual lever freely movable at all times and associated circuit means for governing each of the power operable means, circuit means preventing operation of any derail to normal unless all routes including the derail be unoccupied and all signals governing all routes including the derail be at stop, circuit means locking operation of a track switch unless all routes including the switch be unoccupied and all signals for such routes be at stop and all derails in such routes be at normal, circuit means locking operation of a derail to reverse unless the track switches for a particular route including the derail be properly lined up and for looking all such track switches against operation so long as the derail is in its reverse position, and circuit means preventing the clearing of a signal unless all routes it controls are unoccupied and unless all the switches in said particular route are properly lined up and all the derails in said particular route are at reverse.

3. In a track layout for railway interlocking plants, a plurality of tracks, track switches in the tracks for lining up various routes, including conflicting routes, each including a switch and at least one track, a signal for each end of each route, an individual lever, freely movable at all times, and associated circuit means for govern- .ing each signal, a derail movable to normal and reverse and between each signal and the adjacent track switch, individual power operable means for each derail and for each switch, an individual lever freely movable at all times and associated circuit means for governing each of the power operable means, circuit means preventing operation of any derail to normal unless all routes including the derail be unoccupied and all signals governing all routes including the derail be at stop, circuit means locking operation of a track switch unless all routes including the switch be unoccupied and all signal for such routes be at stop, and all derails in such routes be at normal, circuit means locking operation of a derail to reverse unless the track switches for a particular route including the derail be properly lined up and for locking all such track switches against operation so long as the derail is in its reverse position, the signal circuit means preventing the clearing of a signal unless all 'routes it controls are unoccupied, and all the switches in said particular route are properly lined up and all the derails in said particular route are at reverse, the signal circuit means preventing the clearing of a signal for traffic in one direction over a route unless the signal for traffic in the other direction over the route is at stop.

4. In an interlocking system for railways, in

combination, a track layout, including a track switch, a derail movable to normal and reverse, and a signal, an individual power operable means for operating each of the switch, derail and signal, an individual lever freely movable at all times and an associated circuit, for governing each of the power operable means, a switch lock relay energized only when the derail is normal, 2. derail lock relay energized only when the signal is at stop and the track layout is unoccupied,

the said associated signal control circuit including in series, back points of the switch and derail lock relays.

5. In an interlocking system for railways, in combination, a track layout, including a track switch, a derail movable to normal and reverse, and a signal, an individual power operable means for operating each of the switch, derail and signal, an individual lever, freely movable at all times, and an associated circuit for governing each of the power operable means, a switch lock relay energized only when the derail is normal, a derail lock relay energized only when the signal is at stop and the track layout is unoccupied, the said associated signal control circuit including in series, back points of the switch and derail lock relays, whereby the placing of a derail at reverse causes the deenergization of the switch lock relay, and means whereby the operation of the signal lever to clear the signal causes the deenergization of the derail lock relay to allow the subsequent clearing of the signal through its control circuit including said back point of said derail lock relay.

6. In an interlocking system for railways, in combination, a track layout, including a track switch, a derail movable to normal and reverse, and a signal, an individual power operable means for operating each of the switch, derail and signal, an individual lever, freely movable at all times, and an associated circuit for governing each of the power operable means, a switch lock relay energized only when the derail is normal, a derail lock relay energized only when the signal said associated signal control circuit including in series, back points of the switch and derail lock relays, and the energizing circuit for the switch lock relay including a front point of the derail lock relay.

7. In an interlocking system for railways, in combination, a track layout, including a track switch, a derail movable to normal and reverse, and a signal, an individual power operable means for operating each of the switch, derail and signal, an individual lever freely movable at all times, and an associated circuit for governing each of the power operable means, a switch lock relay energized only when the derail is normal, a derail lock relay energized only when the signal is at stop and the track layout is unoccupied, the said associated signal control circuit including in series, back points of the switch and derail lock relays, means whereby the placing of the derail at reverse deenergizesthe switch lock relay, and means whereby the operation of the signal lever to clear a signal deenergizes the derail lock relay, the energizing circuit for the switch lock relay including a front point of the derail lock relay.

8. In a track layout for interlocking plants, in combination, a wayside signal, a derail, and a track switch, a control circuit, respectively, for each said signal, derail, and switch, a switch lock relay having a front point in the switch control circuit, a derail lock relay having a front point in the derail control circuit, an energizing circuit for the derail lock relay closed only when the signal is at stop, an energizing circuit for the switch lock relay closed only if the derail be normal and the derail lock relay be energized, the signal control circuit including in series a back point of each said lock relays.

9. In a track layout for interlocking plants, in

combination, a wayside signal, a derail, and a track switch, a control circuit, respectively, for each said signal, derail, and switch, a switch lock relay having a front point in the switch control circuit, a derail lock relay having a front point in the derail control circuit, an energizing circuit for the derail lock relay closed only when the signal is at stop, an energizing circuit for the switch lock relay closed only if the derail be normal and the derail lock relay be energized, the signal control circuit including in series a back point of each said lock relays, and means for deenergizing the derail lock relay following lever control of the signal control circuit.

10. In a track layout for interlocking plants, in combination, a wayside signal, a derail, and a track switch, a control circuit, respectively, for each said signal, derail, and switch, a switch lock relay having a front point in the switch control circuit, a derail lock relay having a front point in the derail control circuit, an energizing circuit for the derail lock relay closed only when the signal is at stop, an energizing circuit for the switch lock relay closed only if the derail be normal and the derail lock relay be energized, the signal control circuit including in series a back point of each said lock relays, and means for deenergizing the derail lock relay following lever control of the signal control circuit and prior to the operation of the signal.

NELSON B. COLEY. MORTON C. TWITCHEIL. 

